Milling cutter



Oct. 27, 1953 c. A. BILLMAN 2,656,591

' MILLING CUTTER Filed June 22. 1950 s a r INVENT @ARL A. BIL N ATTORNEY Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE MILLING CUTTER Carl A. Billman, Rochester, N. Y.

Application June 22, 1950, Serial No. 169,676

Claims. 1

The present invention relates to metal cutting tools of the inserted blade type, and more particularly to face mill cutters of the inserted blade type.

In some types of face mill cutters the blades are mounted in open slots cut into the periphery of the cutter heads. The open slots allow entry of dirt and chips with the possibility that dirt or chips may get between a blade and its seat and interfere with chip flow. Furthermore, cutter heads with peripheral slots in them require special care in handling; otherwise the workman may scratch or cut his hands on the edges of the slots. Another disadvantage of slotted cutter heads is that the open slots and the holes drilled for the blade-holding bolts tend to weaken the cutter head. Moreover, the number of blades that can be mounted in a slotted cutter head is limited, for suificient stock must be left between adjacent blades to properly support the blades.

For these and other reasons some types of face mill cutters have blade-receiving recesses broached in them so that the shanks of the blades are mounted inside of the periphery of the cutter heads. The peripheral surfaces of the cutter heads can then be made smooth if the shanks of the blades are serrated on one side and wedges having correspondingly serrated surfaces are used to lock the blades in the bladereceiving recesses. Serrating the blades and serrating the wedges, however, adds to the cost of a cutter. Another disadvantage of this con-- struction is that the blades have to be adjusted in steps to compensate for wear; and the lineness of adjustment is controlled by the pitch of the serrations of blades and wedges. A still further disadvantage of this construction is that the wedges have to be pounded home with a hammer or drift to lock the blades in. position. This causes damaging shocks, which may lessen the accuracy and life of the cutter, and which frequently distort the cutter head. Moreover, it takes time to loosen or tighten awedge.

Because of these objections, face mill cutters have also been made with blade-receiving recesses broached in the cutter heads but with the blades locked in position by set-screws and adjusted for wear by adjusting screws. The adjusting screws allow of an infinitely fine adjustment of the blades. However, it is difiicult to hold the blades securely enough with set-screws. Moreover, for access, the holes for the set-screws must be drilled from the periphery into the cutizer head. This destroys the smoothness of the peripheral surface of the cutter head. More- V that do not have to be removed from the cutter head in order to release the blades, and that. therefore, will not be removed from the cutter head and get lost.

A further object of the invention is to provide a rotary cutting tool having a novel means for locking the blades in position, which is so constructed that it cannot be removed from the cutter head in the act of locking or releasing a blade.

Another object of the invention is to provide a blade lock for the blades of inserted blade type cutters which is of the wedge type which can be released or locked with a very slight turn of a locking nut.

Another object of the invention is to provide a rotary cutting tool which can be handled with greater safety and in which the blades can be mounted with more accuracy because the cutter head has a smooth, solid outside peripheral surface, but in which at the same time the blades can be adjusted with an infinitely fine adjustment,

Another object of the invention is to provide a rotary cutting tool in which infinite adjustment of the blades can be obtained without having to drill any holes in the cutter head from the outside thereof and without requiring that the blades be mounted in open slots.

Another object of the invention is to provide a rotary cutting tool in which the blades can be placed closer together than in conventional cutters, and in which, therefore, a greater number of blades can be placed in a cutter head of a given diameter without impairing the strength of the cutter head.

Another object of the invention is to provide wedges for locking blades in a cutter head which is so constructed as to permit a wider tolerance in the manufacture of the blades and which will align themselves against the blades in the act of clamping the blades in the blade sockets.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims.

In the drawing:

Fig. 1 is a fragmentary end view of a facemill cutter made according to one embodiment of this invention;

Fig. 2 is a section on the line 2-4 of Fig. 1, looking in the direction of the arrows;

Fig. 3 is a section on the line 33 of Fig. 2,, looking in the direction of the arrows;

Fig. 4 is a fragmentary side elevation of the cutter; V

Fig. 5 is a sectional View in a plane parallel to the plane of Fig. 3 showing a blade of the cutter, the wedge member for locking the blade in the cutter head, and the nut for moving the wedge member to and from locking position;

Fig. 6 is a section corresponding to Fig. 5 showing a modified form of wedge locking member;

Fig. '7 is a section corresponding to Figs. 5 and 6 and showing a still further modified form of locking member and showing, also, a modified form of blade;

Fig. 8 is an end view of the wedge locking member of Fig. '7 on an enlarged scale;

Fig. 9 is a fragmentary sectional view Of another type of rotary cutter made according to this invention; and

Fig. 10 is a fragmentary side elevation of this cutter.

Referring now to the drawingsby numerals of 5 It is provided H formed to a generally equilateral triangular cross-section with one side of the triangle facing generally radially and outwardly of the cutter, and is threaded, as denoted at 36, to receive an adjusting nut 3'5. The diameter of the thread is such that the three side walls of each socket are smooth adjacent their ends and are intersected by the thread between their ends as clearly shown in Figs. 2 and 3.

The recesses or sockets 24 are adapted to receive the cutting blades which are of equilateral triangular cross-section. The outside end face of the cutter head is dished as denoted. at 3| to form a peripheral ring or flange 32. The blades 30 are mounted in the recesses or sockets 24 so that their cutting ends project beyond the peripheral flange 32 of the cutter head; and their projecting portions are sharpened in con.- ventional fashion to form the usual cutting edges 34 and 35. Recesses 39 are providedin the head in front of the several blades for chip clearance.

The adjusting nuts 31 abut against the inner ends of the blades. blade longitudinally of its socket to control the amount that the blade projects beyond the face of the cutter head and to compensate for wear and the amount of stock removed from the blade during sharpening.

Each blade is adapted to be held in the cutter head by a wedge-shaped clamping member 40 which is mounted in a hole 4| in the cutter head along side the blade socket, and preferably in- Each nut serves to adjust a clined at right angles to the axis of the blade socket. Each wedge member 49 has a flattened portion 42 to engage the confronting side surface 44 (Fig. 5) of a blade 30 and each wedge member terminates at its outer end in a threaded portion 48. The diameter of the threaded portion 48 is slightly less than the diameter of the adjacent clamping part of each wedge member 40, as clearly shown in Fig. 5, so that a shoulder 59 is formed between the threaded portion 48 and the adjacent part of each wedge member.

Each Wedge member 40 is adapted to be moved to and from locking position by a nut 45 that engages the threaded portion 48 of the wedge member. In the preferred embodiment, each nut 45 has a right-hand thread 46 on its outside periphery, which is adapted to thread into a socket 49 formed in the cutter head 20, and has a lefthand thread 41 on the inside of its bore, which. threads onto the left-hand threaded portion 48 of the wedge pin 49.

Before assembly of a wedge member 40 and its associated nut 45 into the cutter head 29, the nut is threaded onto the threaded portion 48 of the wedge member until it abuts against the shoulder 59 of the wedge member. When the wedge member is inserted into its hole 4| in the cutter head, the nut is rotated in socket 49 until the flat 42 on the wedge member is in a plane which will be parallel to and abut against the confronting face 44 of a blade 35 when that blade is inserted in its blade socket 24. Then the blade is placed in its socket 24. The face 44 of blade 30 abutting against the flat 42 of the wedge member now holds the wedge member against rotation with the nut 45. When the nut 45 is threaded further into socket 49, then, the wedge member 40 is moved bodily axially inward- 1y to clamp the blade 30 rigidly in the socket 24.

To remove a blade from its socket 24, the nut 45 needs only to be unthreaded sufficiently to move wedge member axially outwardly sufliciently to disengage flat side 42 of the wedge member from side 44 of the blade. Then the blade can be lifted out of its socket. As long as the blade remains in its socket wedge member 40 and its nut 45 cannot be removed from the cutter head, for the nut 45 can be unthreaded onl until the shoulder. 59 of the wedge member 40 abuts against the nut. Then the shoulder 59 of the wedge member acts as a lock against the nut, preventing further unthreading movement of the nut. It is only after the blade is removed, that nut 45 can be further unthreaded, for then there is nothing any longer holding the wedge member against rotation with. the nut, and the wedge member and nut can then rotate together and. be removed together from the cutter head. Since there is no object, however, in further unthreading the nut 45 after the blade is removed, there is no incentive to further unthread the nut after the blade is removed. The nut and wedge member are therefore left in the cutter head and will not be lost. 7 v

It takes but a fraction of a turn of the nut to release the blade; and the blade can readily be picked out of the socket without having to be hammered out. The threaded portions 36 of the "blade sockets afford relief with reference to the sides of the blades so that there is no appreciable friction resisting removal of the blades from their sockets- Sockets 43 are provided in the nuts 45 to re.- ceive hexagonal wrenches for turning them; If desired, similar sockets 43', as shown in Fig. 5,

may be provided in the heads of the wedge members 40 to allow the wedge pins to be turned separately from the nuts for movement to or from clamping position.

While it is preferred to form the nut 45 with threads of opposite hand on its inside and outside surfaces as described, it is to be understood that threads of the same hand but of different pitch might be used instead on the outside and inside of the nut thereby affording a differential action. In this latter case, however, the hand of thread on the outside of the nut would have to be such that the nut would be threaded outwardly to release a wedge pin. The differentially threaded nut might be just as fast in action as the nut provided on outside and inside with threads of opposite hands but the differentially threaded nut might be threaded out of the head and misplaced.

In Fig. 6 a modification of the locking wedge is shown. Here, the shank portion. of locking wedge 40' has a flattened gripping surface 42' on it which converges toward the outer threaded end 48' of the wedge member. A nut 45 is used for moving the wedge to or from looking posi. tion. This nut is threaded into a socket 49 in the cutter head and again has an external threaded surface 46 of one hand and an internal threaded surface 41 of opposite hand. The latter threaded surface meshes with threaded portion 5 48 of the wedge pin In this case, when the nut is threaded into the head the wedge pin is propelled into unclamping position, whereas when the nut 46 is threaded outwardly, the wedge pin 40 moves in its socket 4| to clamping position.

By making the wedge pin as shown in Figs. 7 and 8 at 40 with a crowned surface 42" that engages the confronting surface of the blade 30, greater tolerance can be had as to the blade surface and the sockets 4|". This crowned surface 42" has a localizing contact with the blade. and permits the wedge pin to align itself against the blade. The operation of the wedge pin is otherwise the same as the first described embodiment of the invention.

Fig. 7 also shows a modified form of blade. This blade 30 is a truncated triangular shape in. transverse cross-section, whereas the blades 30 previously described are of equilateral triangular shape in transverse cross-section. The blade 30 has a flat rear surface 54 approximately parallel to its front face 44'. The shape of blade 30' has several advantages over the blade 30.

The blades can be placed closer together than i can triangular shaped blades; and therefore a greater number of blades can be mounted in a cutter head of a given diameter. The flat 54 at the back of the blade provides a surface against which the index or guiding finger of a blade-sharpening machine can be seated so that the grinding wheel can be rotated into the blade exerting a force against the locating finger. The truncated blade shape also provides greater chip clearance between successive blades.

In all of the above-described embodiments of the invention, the sides of the blades fit against the Walls of the blade-receiving recesses or sockets, which walls thus provide solid backing for sustaining the forces applied to the blades during cutting. Adjustment of a blade for wear is effected by loosening the wedge member and rotating the adjusting screw 31 to shift the blade endwise in its socket or recess.

In Figs. 9 and 10 I have shown a further applithread 51 of opposite hand in its bore.

cation of the invention. Here 50 denotes amilling cutter having blade-receivingslots 51 in its periphery adapted to receive cutting blades 52. These blades are held in the slots by wedge members 53 which are similar to those already described. These wedge members are moved to and from clamping positions by nuts 55 that thread into the cutter head. Each nut 55 has a nection with several different embodiments there- .of, it is capable of further modification, and this application is intended to cover any variations,

uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what I claim is:

1. A cutting tool comprising a rotary head having a plurality of blade-receiving sockets therein arranged about its axis, a blade mounted in each socket, each blade having a plane side surface, and means for securing each blade in its socket comprising a clamping member which is mounted to be reciprocable axially in a recess in said head that opens at one side into said socket and that ex tends at right angles to the axis of said socket, each clamping member having a wedge-shaped head which engages the plane side of the associated blade, and each clamping member having a threaded shank integral with said wedge-shaped head, and a nut having an external threaded surface which is threaded into the recess and an internal threaded surface which threads onto said shank, the external threaded surface of the nut being threaded differently from its internal threaded surface.

2. A cutting tool comprising a rotary head hav ing a plurality of blade-receiving sockets therein arranged circularly about its axis and extending in the general direction of its axis, said head having a smooth, peripheral surface, a blade mounted in each socket, each blade having a plane side surface, means for adjusting each blade axially of its socket, and means for securing each blade in its socket comprising a clamping member which is reciprocable in a direction inclined to the axis of the head in a recess that opens into the socket and'that extends at right angles to the axis of the socket but that is closed at its outer end, said clamping member having a wedge-shaped head, which has a plane surface engaging the plane side surface of the blade, and

having a threaded shank integral with said Wedge-shaped head, and a nut having an external surface threaded into the recess and an internal surface threaded onto the shank, the external threaded surface of the nut being of opposit hand to its internal threaded surface.

3; A cutting tool comprising a rotary head having a plurality of blade-receiving sockets therein arranged about its exis, a blade mounted in each socket, each blade having a plane side surface, and means for securin'g'eaoh blade in its socket comprising a clamping member which is reciprocable in a direction inclined to the axis of epeeguee the 'head "in a recess that opens into the socket and that "extendsat right angles to the axis of the socket, said clamping member having a wedge-shaped head, which has acrowned surface engaging the'p'l'ane side surface of the blade, and having a "threaded "shank integral with said wedge-shaped head, and 'a nut having an external surface threaded into the recess and an internal surface threaded onto the shank, the external threaded surface of the nut being threaded differently from its internal threade surface.

'4. -A cutting tool comprising a rotary head having a smooth peripheral surface and an annular -peripi ieral flange at'one end, and having a pluralit-y of circularly arranged blade-receiving sockets extending through the flange and rest of the head and diverging outwardly from the axis of the head toward said one end of the head, each socket being of polygonal shape in crosssect-ion'and having plane seating surfaces, a blade mounted in each socket with its cutting portion projecting from its socket beyond the peripheral flange, each blade being of polygonal shape in cross-section and having plane sides to fit into its socket, and means for securing each blade in its socket comprising a clamping member which is reciprocable in "the head in a recess that opens into the socket and that extends approximately at'right angles to the axis of the socket, said clamping member having a wedge-shaped head engaging the confronting side of the blade and. having an integral threaded shank, and a nut having an external surface threaded into the recess from the inside of the peripheral flange and having an internal surface threaded. onto the shank, the external threaded surface of the nut being of opposite hand to its internal threaded surface.

5. A cutting tool comprising a rotary head hav- "ing a smooth "peripheral surface and an annular peripheral flange at 'one end, and having a plurality of circularly arranged blade-receiving sockets extending through the flange and rest of the head and diverging outwardly from the axis of the head toward said one end of the head, each socket being of polygonal shape in cross-section, a blade mounted in 'each socket with its cutting portion projecting from its socket beyond the peripheral flange, each blade being of polygonal shape in cross-section to :fit into its socket and having plane side surfaces, and means for securing each blade in its socket comprising a clamping member which is reciprocable in the head in a recess that opens into the socket and that extends outwardly from the inside of said peripheral flange approximately at right angles to the axis of the socket, said clamping member having a wedge-shaped head, which is crowned, that engages the confronting plane side of the blade, and having an integral threaded shank, and a nut having an external surface threaded into the recess and an internal surface threaded onto the shank, the external threaded surface of the nut being of opposite hand to its internal threaded surface, said nut being mounted in "the recess to be accessible'from the "inside of the peripheral flange.

6. A cutting tool comprising a rotary head having a smooth peripheral surface and an an- 'nular peripheral flange at one end, and having a plurality of blade-receiving sockets which extend through the flange to the opposite end of the head and whichdiverge outwardly from the axis ofthe head from the *latter end of the head 8 toward the flange end, each socket being of polygonal shape in cross-section and having plane seating surfaces, each socket being threaded along its length, the threaded portion being of a diameter to provide concave portions in the sides of the socket, a'b'lademounted in each socket with its cutting portion projecting from its socket beyond the peripheral flange, each blade being of polygonal shape in cross-section to fit into its socket and having plane sides, means for securing each blade in its socket with its sides seating against the plane seating surfaces of its socket, comprising a clamping member which is reciprocable in the head in a recess that opens into the socket and that extends outwardly from the inside of said peripheral flange approximately at right angles to the axis of the socket and that is closed at its outer end, said clamping member having a wedge-shaped head engaging the confronting side of the blade and having an integral threaded shank, and a nut having an external surface threaded into the recess and an internal surface threaded onto the shank, the external threaded surface of the nut being right handed and the internal threaded surface of the nut being left handed, said nut being threaded into'the recess to be accessible from the inside of the peripheral flange, and a nut threaded into each socket to be adjustable axially thereof to adjust the associated blade axial l s in the socket.

7. A cutting tool comprising a rotary head having a plurality of blade-receiving sockets therein, a blade mounted in each socket with its cutting portion projecting from the socket beyond one side face of the head, said blade being of approximately trapeziform shape in transverse cross-section with parallel sides at the front and rear respectively of the blade considered in the direction of rotation of the cutting tool, and means for securing each blade in its blade socket, comprising an axially movable clamping member having :a threaded shank portion and a wedge-shaped head integral with said shank portion, said wedge-shaped head having a surface inclined to the axis of the clamping member and adapted to engage a side of said blade, said rotary head having a hole therein which extends at right angles to said blade-receiving socket and which communicates with said bladereceiving socket and which receives said clamping member, and a nut threaded internally onto the threaded shank portion of said clamping member and threaded externally into said hole, the portion of the nut which threads into the hole being differently threaded from the portion which threads onto said shank portion of said clamping member.

8. A cutting tool comprising a rotary head having a smooth peripheral surface and an annular, peripheral'flange at one end, and having a plurality of circularly arranged blade-- receiving sockets extending through the flange and the rest of the head and diverging outwardly from the axis of the head toward said one end of the head, each socket being of polygonal shape in cross-section and having plane seating surfaces, a blade mounted in each socket with its cutting portion projecting from its socket beyond said peripheral flange, each blade having plane sides and being of polygonal shape in cross-section to seat against the seating surfaces of its socket, and means for securing each blade in its socket comprising -a clamping member radially outwardly from the inside of said peripheral flange approximately at right angles to the axis of the socket but that is closed at its outer end, said clamping member having a wedgeshaped head engaging the confronting side of the blade and having an integral threaded shank, and a nut having an external surface threaded into said recess from the inside of said peripheral flange and having an internal surface threaded on said shank, the external threaded surface of the nut being threaded diiferently from its internal surface.

9. A cutting tool comprising a rotary head having a smooth peripheral surface and an annular, peripheral flange at one end, and having a plurality of circularly arranged blade-receiving sockets extending through the flange and the rest of the head and diverging outwardly from the axis of the head toward said one end of the head, each socket being of polygonal shape in cross-section, a blade mounted in each socket with its cutting portion projecting from its socket beyond said peripheral flange, each blade having at least one plane side and being of polygonal shape in cross-section to fit into its socket, and means for securing each blade in its socket comprising a clamping member which is reciprocable in the head axially in a recess that opens into the socket and that extends outwardly from the inside of said peripheral flange approximately at right angles to the axis of the socket, said clamping member having a wedge-shaped head which is crowned and which engages said plane side of the blade, and having an integral shank, and a nut having an external surface threaded into said recess adjacent the inside of said peripheral flange and having an internal surface threaded onto said shank, the external threaded surface of the nut being differently threaded from its internal surface, and said nut being mounted in said recess to be accessible from the inside of said peripheral flange.

10. A cutting tool comprising a rotary head having a smooth peripheral surface and an annular, peripheral flange at one end, and having a plurality of circularly arranged blade-receiving sockets extending through the flange and the rest of the head and diverging outwardly from the axis of the head toward said one end of the head, each socket being of polygonal shape in cross-section and having plane seating surfaces. a blade mounted in each socket with its cutting portion projecting from its socket beyond said peripheral flange, each blade having plane sides and being of polygonal shape in cross-section to fit into its socket, and means for securing each blade in its socket comprising a clamping member which is reciprocable in the head axially in a recess that opens into the socket and that extends outwardly from the inside of said peripheral flange approximately at right angles to the axis of the socket but that is closed at its outer end, said clamping member having a wedgeshaped head engaging the confronting plane side of the blade and having an integral threaded shank, and a nut having an external surface threaded into the recess and an internal surface threaded onto said shank, the external threaded surface of the nut being right-handed and the internal threaded surface of the nut being lefthanded, and said nut being accessible from the inside of said peripheral flange, each socket being threaded axially along its length, the threaded portion being of a diameter to provide concave side portions in said socket which afford clearance between portions of the sides of the associated blade and its socket, and a second nut threaded axially in each socket and abutting against one end of the associated blade to adjust the blade axially in the socket.

CARL A. BILLMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 807,166 Grant Dec. 12, 1905 2,367,221 Kraus Jan. 16, 1945 2,369,587 Macafee Feb. 13, 1945 2,382,509 Seiter Aug. 14, 1945 2,500,387 Sheridan Mar. 14, 1950 2,508,437 Thomas et al. May 23, 1950 2,547,789 Skeel Apr. 3, 1951 FOREIGN PATENTS Number Country Date 4,183 Great Britain Apr. 2, 1885 

